Before technology made it possible to forecast the weather and plant crops in all seasons, people of the Arabian Peninsula relied on generational knowledge and the stars to tell them when to go out to sea and when to grow and harvest their food.
This knowledge was the basis of a calendar, now used only by traditional farmers and fishermen, called Al Durour.
The earliest mention of Al Durour on record was 500 years ago. Renowned Arab navigator Ahmad Ibn Majid reportedly used it during his many sea journeys and explorations.
It made local headlines last month when the Suhail [Canopus] star was sighted, signalling the end of the UAE summer and the start of the calendar.
“Al Durour was mentioned since the days of Ibn Majid and it carried on and became part of the Gulf heritage,” said Ibrahim Al Jarwan, a member of the Arab Union for Astronomy and Space Sciences.
“It was also mentioned in old books by sailors in Africa and India, so it is difficult to identify the exact origin or source of the calendar.”
How is Al Durour different to the Gregorian calendar?
The 365-day Al Durour divides the year into four unequal periods - or seasons - based on weather and begins with the appearance of Suhail on August 15.
These four seasons comprise 60 days of extreme summer, 100 days of spring-summer, 100 days of winter and 100 days of Autumn. The five remaining days, known as Al Masareeq, are added to one of the seasons depending on how early or late each season begins, to complete the annual 365 days.
Each of these seasons is called a Dur - the singular word for Durour. Each Dur is further divided into blocks of 10 days, while the 60 days’ extreme summer Dur is divided into six blocks.
What is Al Durour used for?
“The main purpose for the Al Durour calendar is to forecast the sea weather conditions,” said Sakher Saif, head of the Amateur Astronomy League.
“For those who go pearl diving, it was vital for them to know when to go or refrain from sailing due to bad conditions.”
The calendar was also used by farmers to plan dates for planting or harvesting specific crops, including watermelon and soft dates in August and melon in July.
The rising of Suhail in Al Durour also indicates the start of cooler temperatures.
But, Mr Al Jarwan said, this does not mean summer has ended just yet.
“[It is] like when we say the tea or food became cold. It does not mean it is [fridge] cold, it just means it is not extremely hot any more.”
The masterminds behind Al Durour understood this concept about temperature in the Gulf very well and so split summer into two fragments, rather than inaccurately placing a Spring season on the calendar.
The summer Dur falls between the last 10 days of March and end of June but there is also an extremely hot summer Dur, which includes July and August.
The extremely hot summer is known as Al Qaydh - a word taken from the Arabic verb yqaydhoon, which is when people historically moved to cooler areas of the country for the summer.
“During [Al Qaydh], the residents used to yqaydhoon; they moved from then internal areas of Abu Dhabi and Al Dhafra,” said Hasan Al Naboodah, dean of college of humanities and social sciences at UAE University.
“The women, children and elderly moved to Al Ain, where the farms were, to take care of the palm trees and to store the soft dates, while the men went to dive in Delma Island.
“At the end of the Qaydh period, they reunited in internal areas.”
Who still uses Al Durour today?
While modern technology may have replaced Al Durour in many ways, some of its terms continue to be used today.
“When the end of February approaches, it usually gets hotter so people assume that summer has started already,” said Mr Naboodah.
“Then it becomes extremely cold again for a period of 10 days; so there used to be a myth that when it got really hot an old lady shaved the wool off her sheep, then one week later when it got really cold they died from the cold.”
Locally, this chilly period is referred to as Al Husoum, he said.
An old saying goes “bard al husoom tbaye; el khebel lehafa”, essentially warning that only fools sell their winter blankets before Al Husoum.
Al Durour now can be found on handmade charts designed personally by experts such as Mr Saif. Traditionally, however, it was engraved in the memory of the people.
“Just like we know the months of the year off by heart, they used to know Al Durour off by heart,” said Mr Al Naboodah.
“Back in the old days, one used to know nothing other the desert around him and the stars above him, so he would obviously learn it by heart.
“Some old men, who still live in the mountains, still use it and know it off by heart,” said Mr Al Naboodah.
Mr Saif said the calendar, once almost forgotten, has had a resurgence in popularity over the past decade or so.
“The community started to pay more attention to their heritage, and that is how it came to be.”
He said the calendar was still relevant to a certain extent.
“However, I wouldn't expect it to be as accurate as the modern technologies.”
Traditionally, Al Durour was used mainly in the UAE, Qatar, parts of Oman and the Eastern areas of Saudi Arabia, where it is known as El Ehsaa.